What is a novel-in-stories?

The Beginning Writer's Answer Book edited by Jane Friedman

A novel-in-stories is a book-length collection of short stories that are interconnected. (One of the very first examples of this genre is The Canterbury Tales; a more recent example is The Girl’s Guide to Hunting and Fishing, by Melissa Bank.) A novel-in-stories overcomes two key challenges for writers: the challenge of writing a novel-length work, and the challenge of publishing a book-length work of unrelated short stories. (Few publishers are willing to publish a short-story collection from an unknown writer.) So, the novel-in-stories helps you sell a story collection like you would a novel—as long as the interconnected nature of the stories is strong and acts as a compelling hook. Another advantage to novels-in-stories is that they afford you the opportunity to publish pieces of your novel in a variety of literary magazines, which might attract the attention of an editor or agent. (Editors and agents often troll literary publications looking for new talent to publish or represent.)